| 摘要 |
PCT No. PCT/EP96/00197 Sec. 371 Date May 28, 1997 Sec. 102(e) Date May 28, 1997 PCT Filed Jan. 18, 1996 PCT Pub. No. WO96/24820 PCT Pub. Date Aug. 15, 1996A leveling instrument has an image-forming objective, a picture-taking spatial resolution optoelectronic detector, and electronics and a computing unit for driving the detector and evaluating the detector signals. The image-forming objective is subdivided into several zones of field depth designed each as a different aperture plate. Corresponding partial zone of the detector are associated to the aperture plate. The partial zones of the detector may also be designed as individual spatial resolution detectors. Since all level indicators, whatever their distance from the levelling instrument, may be sensed in one of the zones of field depth designed as aperture plates and reproduced by said aperture plate, the image-forming objective need not be manually or automatically refocused nor aligned with respect to the target.
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